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When I was a 20-year-old sophomore in college, I found myself in a new and uncomfortable situation. I wasn't slacking off, and I liked the topic, but I didn't know what was going on.
It was a difficult math class, designed to weed out those students who should not continue as math majors. In part, that alone explains my struggles. Looking back on it now, though, I'm pretty sure I responded in exactly the wrong way.
What I did was a twofold strategy: 1) I gave up on trying to understand, and 2) I focused on completing my problems sets any way I could.
I didn't do the reading before class because it didn't make sense to me. I tried to take notes on everything, even when doing so meant that I didn't have time to understand what I was supposedly learning — but I figured it'd help me finish my homework later. Even after class, when I was struggling with a problem set, I didn't read the assignments, because (and this is just so pitiful) I felt like it took too much time.
Instead, I'd just scan through the reading and my notes, looking for symbols that would fit into whatever equation I was working with. Then I'd plug things in here and there hoping to get closer to whatever I was trying to solve or prove.
This two-pronged approach was a disaster. Because of my lack of understanding, I just got further and further behind. And now I don't think I remember any of the math I learned.
I do remember one moment, though, when things went well. I decided to pay attention and really understand one day (not sure why). The professor asked a question and a few people answered it incorrectly. Then I raised my hand, and to the surprise of everyone, I got it right. The professor must have been especially shocked, given that he'd been grading my work up until then. Looking back now, this moment tells me that I could have gotten so much more out of the class. I'm not saying I should have been (or could have survived as) a math major, but I could at least have learned something.
What I should have tried to do was understand the material I was learning. That probably seems obvious, but I don't think it is. I think students sometimes decide not to prioritize understanding.
Studying well is about setting priorities, and when things get tough, people often narrow their focus onto doing the work, and the first thing that drops away is understanding. Unfortunately for me, one of the most basic principles of cognitive psychology is that failing to understand something fully is the easiest way to make sure that information is immediately forgotten. A deep understanding is the surest way to create lasting memories.
When you run across something you don't understand, you have a choice to make. Option 1 is, gloss it over, finish your homework (or whatever), and go on to the next assignment. The next assignment is probably overdue, so I wouldn't blame you.
Option 2 is to stop and take the time to figure it out. This is a tough choice to make. You don't have time, you need to get stuff done now, and slowing down is hard when you want to be speeding up. Plus, the payoff might feel like a vague shimmer in the future.
But I urge you to choose option 2. It's the only way to learn.
How do you do it? It usually requires getting help. Get a tutor; visit the professor during office hours; join a study group; ask a friend. And in my experience, it can be surprising how much catching up you can do if only you allow yourself to take the time to understand whatever it is that doesn't make sense.
That's not to say it's easy. It's not. But the solution is to get help and to strive for understanding.
